JP6746740B2 - Image processing apparatus, image processing method, and program - Google Patents

Description

The present invention relates to an image processing device, an image processing method, and a program that deform an edge portion.

There is a technique for improving the image quality of a printed object by performing image processing for the edge part of the object included in the image data. Japanese Patent Application Laid-Open No. 2004-163242 discloses a technique of identifying an edge portion of an object included in image data by analyzing the image data, and performing a process of expanding (deforming) the edge portion of the object with respect to the identified edge portion. Is disclosed. The patent document 1 further re-analyzes image data including the expanded object to re-specify the edge part of the expanded object, and to re-specify the edge part with respect to the re-specified edge part. Disclosed is a technique for performing a screen process for a computer.

U.S. Patent Application Publication No. 2010/0128314

However, in the technique disclosed in Patent Document 1, the image data is analyzed in order to specify the edge part of the object to be deformed, and the image data is re-defined in order to specify the edge part of the object after the deformation. Parsed. Thus, re-analyzing the image data causes an increase in calculation cost.

The image processing apparatus according to the present invention is an image processing apparatus for thickening the width of the object included in the image data from the image data and the pixel in the edge on the inside of the object, the outer edge on the outside of the object specifying means for specifying a pixel, by overwriting the value of the pixels in said edge of said object with respect to a pixel of said outer edge of said object specified by said specifying means, thickening the width of the object a thickening processing means, for the object after the width is changed by the thickening processing unit, for pixels outside the edge specified by said specifying means, image processing means for performing predetermined image processing for edge It is characterized by having.

According to the present invention, it is possible to perform predetermined image processing on the edge portion of a deformed object without reanalyzing the image data.

It is a figure which shows the structure of the image processing apparatus used in description of 1st Embodiment. It is a figure which shows the structure of the image processing part used by description of 1st Embodiment. FIG. 6 is a diagram showing an example of image data before and after thickening processing used in the description of the first embodiment. It is a figure which shows an example of the data after a filter process used in description of 1st, 3rd, 4th embodiment, and edge data. 6 is a flowchart showing a process of an edge data generation unit used in the description of the first embodiment. It is a figure explaining the filter process used in description of 1st Embodiment. 6 is a flowchart showing a threshold determination process used in the description of the first embodiment. FIG. 9 is a diagram showing a pattern for determining an edge after a thickening process used in the description of the first embodiment. It is a figure which shows the case which should cancel the thickening process used in description of 1st Embodiment. It is a figure for demonstrating the pattern matching used in description of 1st Embodiment. It is a figure which shows the flowchart of the thickening process used in description of 1st Embodiment. It is a figure which shows the structure of the image processing part used by description of 2nd Embodiment. It is a figure which shows the method of referring to the edge position after the thickening process used in description of 3rd Embodiment. 9 is a flowchart showing processing of an edge data generation unit used in the description of the third embodiment. It is a figure which shows the pattern which determines the edge after the thickening process used by description of 3rd Embodiment. It is a figure which shows the method of referring to the edge position after the thickening process used in description of 4th Embodiment. It is a flowchart which shows the process of the edge data generation part used by description of 4th Embodiment.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. The configurations shown in the following embodiments are merely examples, and the present invention is not limited to the illustrated configurations.

<First Embodiment>
In the first embodiment, as an example of deforming an object in image data, a process of expanding an edge portion by one pixel in four directions of up/down/left/right will be described. Then, an image processing apparatus that switches the image processing method between the edge portion of the thickened object and the inside of the thickened object will be described.

FIG. 1 shows the configuration of a printing apparatus including the image processing apparatus according to this embodiment. The printing apparatus according to this embodiment includes a controller 100, an operation unit 106, and a printing unit 107. The printing device is connected to the network 108.

The controller 100 receives PDL data from the network 108. PDL is an abbreviation for Page Description Language, which is a command system generally used for expressing drawing on a page. Further, the controller 100 acquires the setting information of the “width for thickening the object” set by the user via the operation unit 106. Then, the controller 100 performs the image processing based on the setting information of the “width of thickening the object” after converting the PDL data into the image data in the bitmap format. Details will be described later. Then, the controller 100 outputs the image data in the bitmap format subjected to the image processing to the print unit 107.

The operation unit 106 may be, for example, a liquid crystal touch panel in this embodiment. The operation unit 106 receives each operation from the user. For example, the operation unit 106 transmits to the controller 100 the setting information of “width to thicken object” according to each operation from the user.

The printing unit 107 prints an image on a paper medium using a color material such as ink or toner based on the image data in the bitmap format acquired from the controller 100.

[Description of Controller 100]
The configuration of the controller 100 will be described. The controller 100 has a CPU, ROM, and RAM (not shown). The CPU expands the program recorded in the ROM into the RAM and executes the program to implement the PDL data receiving unit 101, the PDL processing unit 102, and the image processing control unit 105. Further, in the present embodiment, the rendering processing unit 103 and the image processing unit 104 are assumed to be mounted as a semiconductor integrated circuit. Of course, the rendering processing unit 103 and the image processing unit 104 may be implemented as programs executed by the CPU.

The PDL data receiving unit 101 receives PDL data from the network 108 and outputs it to the PDL processing unit 102.

The PDL processing unit 102 interprets the drawing command expressed by the PDL data received by the PDL data receiving unit 101 and outputs the drawing instruction to the rendering processing unit 103.

The rendering processing unit 103 generates image data in bitmap format based on the drawing instruction output from the PDL processing unit 102, and outputs the generated image data to the image processing unit 104. The image data has density information for four colors of color materials (that is, process colors) handled by the print unit 107, for example, cyan, magenta, yellow, and black. Then, each pixel of the image data has density information of 8-bit gradation of 0 to 255, respectively.

The image processing control unit 105 acquires the setting information of “width of thickening object” from the operation unit 106. Based on this setting information, the image processing control unit 105 causes each unit of the image processing unit 104, which will be described later, to have a “position of the edge portion before thickening the object” and a “position of the edge portion after thickening the object”. The image processing unit 104 is instructed how to determine. Specifically, in the edge data described later, which value indicates the “position of the edge portion before thickening the object” and “the position of the edge portion after thickening the object” Instruct the processing unit 104. Details will be described later.

The image processing unit 104 executes each process based on the image data acquired from the rendering processing unit 103 and the instruction set by the image processing control unit 105. Details of this processing will be described later in [Description of Image Processing Unit 104]. Then, the image processing unit 104 outputs the bitmap-format image data on which the respective processes have been executed to the printing unit 107.

[Description of Image Processing Unit 104]
Next, details of each processing of the image processing unit 104 will be described. FIG. 2 is a diagram showing the configuration of the image processing unit 104. The image processing unit 104 includes a memory buffer 201, an edge data generation unit 202, a thickening processing unit 203, an undercolor removal processing unit 204, a color material application amount restriction processing unit 205, and a screen processing unit 206. The memory buffer 201 sequentially stores the image data in the bitmap format acquired from the rendering processing unit 103. Then, when the image data having a predetermined bandwidth is accumulated, the image data having the bandwidth is output to the edge data generation unit 202 and the thickening processing unit 203.

The edge data generation unit 202 determines “the position of the edge portion before thickening the object” and “the position of the edge portion after thickening the object” of the image data acquired from the memory buffer 201, and includes the information. Generate edge data. Details of the processing of the edge data generation unit 202 for generating this edge data will be described later in [Description of Edge Data Generation Unit 202]. The edge data generation unit 202 outputs the generated edge data to the thickening processing unit 203, the undercolor removal processing unit 204, the color material mounting amount restriction processing unit 205, and the screen processing unit 206.

The edge data is in the same bitmap format as the image data, and has 2-bit information for each pixel. The first bit from the lower order is information about "the position of the edge portion before thickening the object". If the value of the first bit from the lower order is 0, the pixel is not the edge portion before thickening, and if the value is 1, it indicates that the pixel is the edge portion before thickening. Also, the second least significant bit is information about "the position of the edge portion after the object is thickened". If the value of the second least significant bit is 0, the pixel is not the edge portion after thickening, and if the value is 1, the pixel is the edge portion after thickening. Of course, the allocation of these bits is only an example, and if the information indicating "the position of the edge part before thickening the object" and "the position of the edge part after thickening the object" is included, It may be in such a form.

Next, the edge data will be described with reference to FIGS. 3 and 4. FIG. 3 is a diagram in which a part of the object is extracted from the image data. FIG. 3A shows the image data before the thickening process, and FIG. 3B shows the image data after the thickening process. FIG. 4 is a diagram showing the edge data and the data after the filter processing which is a source of generating the edge data. Details of the image data after the thickening process of FIG. 3B and the filter data of FIG. 4 will be described later. Here, the edge data will be described.

Edge data generated from the image data shown in FIG. 3A is shown in FIG. In FIG. 3A, hatched pixels are pixels on which the object is drawn. The edge data of FIG. 4B actually has 2-bit information for each pixel, but for the sake of convenience of description, it is represented by a decimal number in the drawing. That is, in the edge data of FIG. 4B, the pixel to which the numerical value of “1” is attached is the pixel of “the position of the edge portion before thickening the object” and the numerical value of “2” is attached. The pixels that are present are the pixels at the “position of the edge portion after the object is thickened”. Details of the processing for generating edge data as shown in FIG. 4B will be described later.

Based on the edge data acquired from the edge data generation unit 202 and the instruction from the image processing control unit 105, the thickening processing unit 203 determines “the position of the edge portion before thickening the object” and “after thickening the object. Position of the edge portion of “. In the instruction of the image processing control unit 105 according to the first embodiment, it is instructed that the first bit from the lower order of each pixel included in the edge data represents information about “the position of the edge portion before thickening the object”. .. Further, the second bit from the lower order indicates that the information about “the position of the edge portion after the object is thickened” is represented. The thickening processing unit 203 performs a process of thickening an object in the image data acquired from the memory buffer 201, and outputs image data including the thickened object to the undercolor removal processing unit 204. Details of the processing of the thickening processing unit 203 will be described later in [Description of the thickening processing unit 203].

The undercolor removal processing unit 204 determines “the position of the edge portion after thickening the object” based on the edge data acquired from the edge data generation unit 202 and the instruction of the image processing control unit 105. Then, the undercolor removal processing is performed on the edge portion of the image data acquired from the thickening processing unit 203. The undercolor is the minimum density of cyan, magenta, and yellow of each pixel in the image data. This undercolor can be replaced with a black colorant of the same density. By replacing the under color with a black color material, the amount of color material at the edges is reduced, and deterioration of image quality such as bleeding, splattering, and color misregistration is suppressed.

The color material mounting amount restriction processing unit 205 determines “the position of the edge portion after thickening the object” based on the edge data acquired from the edge data generation unit 202 and the instruction of the image processing control unit 105. Then, different color material application amount limiting processing is performed for the edge portion of the image data acquired from the undercolor removal processing unit 204 and other portions. The color material application amount limitation is to limit the total density of the color material per unit area (this is called a color material application amount). This is because when a large amount of coloring material is placed on a paper medium per unit area, poor image quality such as poor transfer/fixing occurs. It is preferable that the color material application amount is limited to a lower value for the edge portion of the object. This is because not only transfer and fixing defects but also image defects such as bleeding and scattering are likely to occur at the edge portion. Therefore, the color material application amount limiting processing unit 205 switches the limit value of the color material application amount between the edge portion and the other portions. For pixels that exceed the color material application amount limit value, processing is performed to uniformly reduce the density of each color material until the color material application amount limit value is reached.

The screen processing unit 206 determines the “position of the edge portion after thickening the object” based on the edge data acquired from the edge data generating unit 202 and the instruction of the image processing control unit 105. Then, a screen process is performed on the image data acquired from the color material amount limitation processing unit 205. At this time, the high-frequency screen is processed on the edge portion, and the low-frequency screen is processed otherwise. This is because a screen with a low screen frequency is not suitable for the edges because it tends to have graininess, but the gradation is smooth and is preferable inside the object.On the other hand, a screen with a high screen frequency has a smooth gradation. This is because there is no graininess and it is preferable for the edge portion of the object.

[Description of Edge Data Generation Unit 202]
The processing of the edge data generation unit 202 is shown in the flowchart of FIG. In step S501, the edge data generation unit 202 applies a Laplacian filter to the entire image data for each color material plate of the image data. This Laplacian filter is a 3×3 matrix filter as shown in FIG. The edge data generation unit 202 performs the convolution calculation of the Laplacian filter of FIG. 6A by referring to the values of the pixel of interest and its adjacent pixels. Then, the edge data generation unit 202 further divides the calculation result of the convolution calculation by 16 and adds an offset of 128 to obtain a value in which the minimum value is 0, the center value is 128, and the maximum value is normalized to 255. Is calculated. The effect of the Laplacian filter will be described. FIG. 6B shows a cross-sectional view of the density distribution of the color material having the dotted line 301 with respect to the image data of FIG. When a Laplacian filter is applied to this and normalization is performed, a distribution as shown in FIG. 6C is obtained. In FIG. 6C, the inside of the edge of the object is larger than the central value 128 and the outside of the edge is smaller than the central value 128. Information about the inside and outside of the object as well as the edge position of the object can be determined based on whether the central value is larger or smaller than 128. This is the effect of the Laplacian filter. Here, the edge portion inside the object is called an inner edge, and the edge portion outside the object is called an outer edge.

In step S502, the edge data generation unit 202 determines whether each pixel is an inner edge, an outer edge, or a non-edge based on the value obtained by applying the Laplacian filter obtained in step S501 to each pixel. Decide Specifically, the edge data generation unit 202 makes a threshold determination for each pixel based on the value obtained in step S501. The purpose of this process is to pick up only edges with a certain strength or more, and to exclude edges where two objects are adjacent to each other. In a region in which two objects are adjacent to each other, a plate having a positive Laplacian filter result and a plate having a negative Laplacian filter result are mixed. If you thicken both objects in such a place, the plates will overlap and another pseudo object will occur. Such processing can be excluded by the processing in step S502.

FIG. 7 is a diagram showing a flowchart of the threshold value determination processing in step S502. In step S701, the edge data generation unit 202 determines whether there is a version of the pixel of interest that exceeds the threshold TH1. If there is a version that exceeds the threshold TH1, it is determined in step S702 whether there is a version that is below the threshold TH2. If there is no version below the threshold TH2, the edge data generation unit 202 determines in step S703 that the pixel of interest is the inner edge that is the inner edge of the object. On the other hand, if there is a version below the threshold TH2 in step S702, it means that the version inside the object and the version outside the object coexist. Such pixels do not require image processing for edges. Therefore, in step S704, the edge data generation unit 202 determines that the pixel of interest is a non-edge. If there is no version exceeding the threshold TH1 in step S701, it is determined in step S705 whether there is a version below the threshold TH2. If there is a version below the threshold TH2, the edge data generation unit 202 determines in step S706 that the pixel of interest is an outer edge that is an outer edge of the object. On the other hand, if there is no version below the threshold TH2 in step S705, the edge data generation unit 202 determines that the pixel of interest is a non-edge.

Data in which the "inner edge", "outer edge", and "non-edge" determined in this way are recorded in a bitmap format for the same number of pixels as the image data is generated. This data will be called "filter data". The actual recording method may be performed by setting the inner edge to 1, the outer edge to 2, and the non-edge to 0 for each pixel of the filter data. FIG. 4A shows filter data generated from the image data of FIG. Here, for the sake of easy understanding of the explanation, the cells indicated by the fill 401 indicate pixels at the inner edge, and the cells indicated by the fill 402 indicate pixels at the outer edge.

Next, returning to the flowchart of FIG. 5, the description will be continued. In step S503, the edge data generation unit 202 determines that the pixel for which “inner edge” is recorded in the filter data is “the position of the edge before thickening the object”. Then, the edge data generation unit 202 records "the position of the edge portion before thickening the object" in the edge data by setting 1 at the first bit from the lower value of the pixel of the edge data.

In step S504, the edge data generation unit 202 determines the “position of the edge portion after thickening the object” based on the arrangement pattern of “inner edge”, “outer edge”, and “non-edge” recorded in the filter data. As a determination method, pattern matching of all patterns shown in FIG. 8 is performed on the filter data. In FIG. 8, the cell surrounded by a thick frame is the pixel of interest, and the cells described as “inside”, “outside”, and “non” are the pixels that match the inner edge, the outer edge, and the non-edge in order, respectively. Show. Also, the shaded cells indicate pixels that indicate "the position of the edge portion after thickening the object" when the patterns match. Further, for each pattern, a pattern obtained by rotating the basic pattern by 90 degrees, 180 degrees, or 270 degrees is also used as a pattern. This is because the thickening directions in the first embodiment are up, down, right, and left, and there is no direction dependency. The edge data generated by applying this pattern matching to the filter data of FIG. 4A becomes the edge data shown in FIG. 4B as described above. As described above, the value of “1” indicating “the position of the edge portion before the object is thickened” is attached to the pixel at the inner edge. Further, as a result of the pattern matching shown in FIG. 8, for each pixel (that is, the pixel at the outer edge) matching the pattern 3, the value of “2” indicating “the position of the edge portion after the object is thickened” is It is attached. A value of "0" indicating a non-edge is attached to the other pixels.

Next, the reason for using the pattern of FIG. 8 will be described in detail. The "position of the edge portion after thickening the object" is basically the outer edge adjacent to the inner edge in the upper, lower, left, and right directions. Therefore, the pattern 3 is a pattern for detecting such an arrangement. However, not all outer edges are “positions of the edge portion after the object is thickened”. That is a case in which two objects are drawn close to each other, as shown in FIGS. 9A and 9D, in which two objects are drawn within a distance of 2 pixels. 9A and 9D show image data, and the hatched pixels indicate the pixels of the object. The filter data generated for FIGS. 9A and 9D are shown in FIGS. 9B and 9E, respectively. When this outer edge is defined as “the position of the edge portion after the object is thickened”, the two objects are combined after the object is thickened. Therefore, in the case where two inner edges exist within 3 pixels across the outer edge, the inner edge is “not the outer edge” and “the position of the edge portion after the object is thickened” so that the object is not thickened. And Patterns 4 and 5 in FIG. 8 are patterns for detecting such an arrangement. Edge data generated from FIGS. 9A and 9D are shown in FIGS. 9C and 9F, respectively. As described above, in the pixel at the inner edge, the first bit from the lower order indicating “the position of the edge portion before thickening the object” is “1”. Further, in the pixel at the inner edge, the second bit from the lower order indicating "the position of the edge portion after thickening the object" is "1". Therefore, in the edge data shown in FIGS. 9C and 9F, the pixel at the inner edge is given a value of 3 in decimal notation. It should be noted that the outer edges other than in the adjacent direction coincide with the pattern 3 in FIG. 8, so that the second least significant bit indicating “the position of the edge portion after thickening the object” is “1” (that is, 10). 2) is attached in the hexadecimal notation.

Further, in pattern 3 of FIG. 8, the outer edge adjacent to the inner edge is a non-edge, but it may be the outer edge. It is only necessary that the case next to that is an inner edge case (pattern 4 and pattern 5). For example, FIG. 10A shows image data representing an oblique line or curved figure. The filter data corresponding to the image data of FIG. 10A is as shown in FIG. As described above, in the first embodiment, the thickening directions are up, down, right, and left, and there is no dependence on the direction. Therefore, only the pattern 3 can thicken such diagonal lines and curves. Is. However, as will be described in the third embodiment described later, in a mode in which the direction of thickening is limited to a certain direction, the filter data as shown in FIG. It is not possible. Therefore, by preparing the pattern 1 and the pattern 2 of FIG. 8, the diagonal line in FIG. 10B can be thickened in the horizontal direction. Pattern 1 and pattern 2 are patterns for detecting such an arrangement.

Based on the above reason, the patterns 1 to 3 in FIG. 8 detect a pattern in which the outer edge is “the position of the edge portion after the object is thickened”. Further, patterns 4 to 5 are patterns in which the inner edge is “the position of the edge portion after the object is thickened”.

In this way, the processing of the edge data generation unit 202 makes it possible to specify the edge position after the thickening before the thickening processing.

[Explanation of fattening processing unit 203]
The processing of the thickening processing unit 203 will be described. The thickening processing unit 203 realizes a process of thickening the object by overwriting the pixel value of “the position of the edge portion before thickening” on the pixel of “the position of the edge portion after thickening the object”.

FIG. 11 is a diagram showing a flowchart of processing of the thickening processing unit 203. In step S1101, for the target pixel of the image data, the thickening processing unit 203 determines whether 1 is set at the second bit of the pixel of the corresponding edge data. If 1 is not set at the second bit, it is not "the position of the edge portion after the object is thickened", and the process is terminated and the process proceeds to the next pixel. If 1 is set in the second bit, it is further determined in step S1102 whether 1 is set in the first bit. When 1 is set at the 1st bit, it indicates that the edge position does not change before and after the thickening process, and thus the process is terminated and the process proceeds to the next pixel. If 1 is not set in the 1st bit, in step S1103, among the pixels adjacent in the up/down/left/right direction, the pixel in which 1 is set in the 1st bit is detected. If an adjacent pixel in which 1 is set at the 1st bit is found, the value of that pixel in the image data is overwritten on the value of the pixel of interest in step S1104.

By performing the above processing on the entire image data and edge data, the object of the image data can be thickened by one pixel in the upward, downward, left, and right directions. As an example, FIG. 3B shows image data after thickening an object based on the image data of FIG. 3A and the edge data of FIG. 4B.

As described above, according to the first embodiment, “the position of the edge portion after thickening the object” is determined before thickening the object of the image data. As a result, after thickening the object, it is possible to switch the image processing method between the edge portion of the object and the inside of the object without determining the position of the edge portion again.

In the above-described first embodiment, an example in which the width of the object in the image data is widened is described as an example of the modification processing of the object, but the modification processing may be processing of narrowing the width of the object. Specifically, the pattern used for the pattern matching in FIG. 8 may be a pattern corresponding to the process of reducing the width of the object. For example, in the case of the basic pattern of pattern 3 in FIG. 8, a pattern including non-edge pixels on the left side of the inner edge is prepared, and the position of the deformed edge is set to the non-edge on the left side of the inner edge. Pixels. In this case, the pixel value of the pixel at the inner edge may be overwritten with the pixel value of the non-edge pixel (pixel outside the object) on the right side of the pixel value to perform the thinning process. Also in the case of the process of reducing the width of the object, the image processing control unit 105 performs the above-described process based on the setting information of the “deformed width of the edge portion after the deformation of the object” acquired from the operation unit 106. be able to.

<Second Embodiment>
In the first embodiment, an example has been described in which after the object of the image data is thickened, various kinds of image processing are performed based on the information of the “position of the edge portion after thickening” that is generated in advance.

In the second embodiment, in various image processes before thickening an object, various image processes are performed based on the information of “the position of the edge portion before thickening”. An image processing apparatus that performs various types of image processing based on the information of “position of edge portion after thickening” in various types of image processing after thickening will be described.

FIG. 12 shows the configuration of the image processing unit 104 according to the second embodiment. There are three differences from the first embodiment. First, the undercolor removal processing unit 1203 is in a stage before the thickening processing unit 1204. Secondly, the information on the “position of the edge portion before thickening the object” generated by the edge data generating unit 1202 is output to the undercolor removal processing unit 1203 and the thickening processing unit 1204. Thirdly, the information on the “position of the edge portion after thickening the object” generated by the edge data generating unit 1202 is stored in the thickening processing unit 1204, the color material application amount limiting processing unit 1205, and the screen processing unit 1206. It is to output.

The edge data generation unit 1202 determines “the position of the edge portion before thickening the object” and “the position of the edge portion after thickening the object” for the image data acquired from the memory buffer 1201. However, a total of two pieces of edge data including that information are generated. That is, in the second embodiment, the edge data generation unit 1202 generates edge data that holds information of “the position of the edge portion before thickening the object” in a 1-bit bitmap format. Further, the edge data generation unit 1202 generates edge data that holds the information of “the position of the edge portion after thickening the object” in a 1-bit bitmap format.

The undercolor removal processing unit 1203 acquires edge data having the information of “the position of the edge before thickening the object” from the edge data generation unit 1202, and outputs the edge data to the edge part of the image data acquired from the memory buffer 1201. Color removal processing is performed. The pixel value of the edge portion subjected to the background removal processing is used as the pixel value of the pixel after being thickened in the thickening processing unit 1204 thereafter. Therefore, the same effect as the removal of the undercolor of the edge position after thickening can be obtained.

The thickening processing unit 1204 outputs edge data having information of “the position of the edge portion before thickening the object” and edge data having information of “the position of the edge portion after thickening the object” from the edge data generating unit. To get. Then, a process of thickening the object of the image data acquired from the undercolor removal processing unit 1203 is performed based on these edge data. The thickening method is the same as in the first embodiment.

The color material amount limitation processing unit 1205 and the screen processing unit 1206 acquire edge data having information of “the position of the edge portion after thickening the object” from the edge data generation unit 1202. Then, the color material application amount restriction processing unit 1205 performs image processing on the image data acquired from the thickening processing unit 1204, and the screen processing unit 1206 processes the image data acquired from the color material application amount restriction processing unit 1205. Perform image processing.

As described above, according to the second embodiment, in the image processing before thickening the object, the processing is performed based on the information of “the position of the edge portion before thickening the object”, and in the image processing after thickening the image processing. The processing is performed based on the information of "the position of the edge portion after the object is thickened". As a result, it is possible to switch the image processing method between the edge and the inside both before and after thickening the object of the image data.

<Third Embodiment>
In the first embodiment, the example in which the object in the image data is thickened by one pixel in the four directions of up/down/left/right has been described. As a result, the width of the object is increased by 2 pixels in total. To increase the width of the object by one pixel in total, it is possible to increase the width of the object by one pixel only in a certain direction, for example, two directions of right and bottom. In the third embodiment, the operation unit acquires from the user three types of settings of “0 pixel”, “1 pixel”, and “2 pixel” as the setting of “width of thickening object”, and the width of the object is instructed according to the instruction. To get fat. Then, an embodiment of an image processing apparatus capable of performing appropriate image processing after that will be described. If the width to be thickened is “0 pixel”, it means that the thickening process is not performed. In the case of "1 pixel", for example, it means that the pixel is thickened only in the two directions of right and bottom. In the case of "two pixels", it means that the pixel is thickened by one pixel in the four directions of up/down/left/right as described in the first embodiment.

The configurations of the image processing apparatus 100 and the image processing unit 104 in the third embodiment are the same as those in the first embodiment. Portions having different processing contents from those of the first embodiment will be described.

The operation unit 106 acquires three types of settings of “0 pixel”, “1 pixel”, and “2 pixel” as the setting of “width to thicken object” from the user and notifies the image processing control unit 105.

The image processing control unit 105 determines, based on this setting information, that each unit of the image processing unit 104 determines “the position of the edge portion before thickening the object” and “the position of the edge portion after thickening the object”. The image processing unit 104 is instructed how to do this. Since the "position of the edge part after thickening the object" varies depending on the width of thickening the object, which position is to be determined as "the position of the edge part after thickening the object"? Send the original instructions.

The edge data generation unit 202 determines the position of the edge facing the right or down direction and the edge facing the left or up direction in the image data acquired from the memory buffer 201 before thickening the object. Further, the edge data generation unit 202 determines the positions of the right or downward facing edge and the left or upward facing edge after thickening the object. Then, the edge data including the information is generated. Details of the processing of the edge data generation unit 202 for generating this edge data will be described later in [Description of the edge data generation unit 202 in the third embodiment]. The edge data generation unit 202 outputs the generated edge data to the thickening processing unit 203, the undercolor removal processing unit 204, the color material amount limitation processing unit 205, and the screen processing unit 206.

The edge data in the third embodiment is a bitmap format having the same size as the image data, and has 4-bit information for each pixel. The first bit from the lower order is information about "the position of the edge portion facing right or downward before thickening the object", and if the value is 0, it indicates that the pixel is not the edge portion. Is 1, it indicates that the pixel is an edge portion. The second least significant bit is information about "the position of the edge portion facing left or upward before thickening the object", and a value of 0 indicates that the pixel is not the edge portion. A value of 1 indicates that the pixel is an edge portion. Also, the third bit from the lower order is information about "the position of the edge portion facing rightward or downward after the object is thickened by one pixel", and if the value is 0, the pixel is not the edge portion. If the value is 1, it indicates that the pixel is an edge portion. Further, the 4th bit from the lower order is information about "the position of the edge portion facing left or upward after the object is thickened by one pixel", and if the value is 0, the pixel is not the edge portion. If the value is 1, it indicates that the pixel is an edge portion. FIG. 4C shows edge data generated from the image data shown in FIG. 3A as an example of the edge data in the third embodiment. The edge data in FIG. 4C has 4-bit information for each pixel, but for convenience of explanation, the value of each pixel is represented by a decimal number.

Next, the thickening processing unit 203, the undercolor removal processing unit 204, the color material application amount restriction processing unit 205, and the screen processing unit 206 will be described. These processing methods are the same as those in the first embodiment, but the method of determining "the position of the edge portion after thickening the object" is different from that in the first embodiment. In the first embodiment, the “position of the edge portion after thickening the object” itself is included in the edge data output by the edge data generation unit 202. However, in the third embodiment, the bit of the edge data indicating “the position of the edge portion after thickening the object” differs depending on the setting of the “width to thicken the object” set by the user on the operation unit. ..

When the "width of thickening the object" is set to "0 pixel", the pixel of which the first bit or the second bit of the edge data is "1" indicates the "position of the edge portion after thickening the object".

When the "width of thickening the object" is set to "1 pixel", the pixel of which only the second bit or the third bit of the edge data is "1" is the "position of the edge portion after thickening the object". Is shown. The reason why only the second bit or only the third bit is a pixel of “1” will be described with reference to FIG. Pixels in which only the second bit is “1” in FIG. 4C are pixels indicated by “2” in decimal notation. A pixel in which only the third bit is "1" is a pixel indicated by "4" in decimal notation. Here, the lower left pixel of the inner edge in FIG. 4C is a pixel that is oriented in the “downward direction” before the object is thickened and is also oriented in the “leftward direction”. Therefore, since the first bit and the second bit are "1", they are shown as "3" in decimal notation. This pixel does not become a pixel at the position of the edge portion after thickening because it is thickened downward when it is thickened by an actual one-pixel width. Therefore, when the "width for thickening the object" is set to "1 pixel", the pixel whose second bit or only the third bit of the edge data is "1" is the "edge portion after thickening the object". The position of ".

When the "width of thickening the object" is set to "2 pixels", the pixel whose third bit or fourth bit of the edge data is "1" indicates the "edge position after thickening the object". .. FIG. 13 shows the determination method as described above. The image processing control unit 105 instructs the thickening processing unit 203, the undercolor removal processing unit 204, the color material application amount restriction processing unit 205, and the screen processing unit 206 how to make this determination.

<Details of Edge Data Generation Unit 202 in Third Embodiment>
The process of the edge data generation unit 202 is shown in the flowchart of FIG. First, in step S1401, the edge data generation unit 202 applies a Laplacian filter to the entire image data for each color material plate of the image data. This is the same processing as S501 in the first embodiment.

Next, in step S1402, the edge data generation unit 202 performs threshold value determination on each pixel based on the calculated value of the Laplacian filter, and generates filter data. This is the same processing as S502 in the first embodiment.

Next, in step S1403, the edge data generation unit 202 determines, based on the arrangement pattern of the inner edge/outer edge/non-edge recorded in the filter data, “the edge facing the right or downward before the object is thickened”. Position of the section" is determined. Then, the position is recorded in the edge data. At this time, 1 is set to the first bit from the lower order of the pixel value of the corresponding pixel of the edge data. This determination method may be performed by determining whether the inner edge in the edge data is the pixel of interest and the outer edge exists in the pixel adjacent to the right or below.

Next, in step S1404, the edge data generation unit 202 determines, based on the inner edge/outer edge/non-edge arrangement pattern recorded in the filter data, “an edge facing leftward or upward before the object is thickened”. Position of the section" is determined. Then, the position is recorded in the edge data. At this time, 1 is set to the second lowest bit of the pixel value of the corresponding pixel of the edge data. This determination method may be performed by determining whether the inner edge in the edge data is the pixel of interest and the outer edge exists in the pixel adjacent to the left or above.

Next, in step S1405, the edge data generation unit 202, based on the arrangement pattern of the inner edge, the outer edge, and the non-edge recorded in the filter data, “turns to the right or downward after thickening the object. The position of the edge portion" is determined. Then, the position is recorded in the edge data. In this determination, pattern matching of the pattern shown in FIG. 15A is performed on the filter data. The pattern shown in FIG. 15A corresponds to the pattern of FIG. 8 rotated by 0° and 90°. When the patterns match, 1 is set to the third least significant bit of the pixel value of the pixel of the edge data corresponding to the pixel of the shaded cell.

Next, in step S1406, the edge data generation unit 202, based on the arrangement pattern of the inner edge/outer edge/non-edge recorded in the filter data, “turns left or upward after the object is thickened”. The position of the edge portion" is determined. Then, the position is recorded in the edge data. In this determination, pattern matching of the pattern shown in FIG. 15B is performed on the filter data. The pattern shown in FIG. 15B corresponds to the pattern of FIG. 8 rotated by 180 degrees and rotated by 270 degrees. When the patterns match, 1 is set at the 4th bit from the lower order of the pixel value of the pixel of the edge data corresponding to the pixel of the shaded cell.

Finally, in step S1407, the edge data generation unit 202 outputs the generated edge data to the thickening processing unit 203.

As described above, according to the third embodiment, the operation unit acquires from the user three types of settings of “0 pixel”, “1 pixel”, and “2 pixel” as the width for thickening the object. Then, after thickening the width of the object according to the instruction, it is possible to perform appropriate image processing on the edge portion of the object and on the inside of the object.

In addition, in the third embodiment, when "1 pixel" is designated as the thickening width of the object, an example of thickening in the right and downward directions has been described. However, the thickening direction is not limited to this, and for example, the left and upper directions may be thickened.

<Fourth Embodiment>
In the first embodiment, the example in which the object in the image data is thickened by one pixel in the four directions of up/down/left/right has been described. As a result, the “width of the object” is thickened by 2 pixels in total. However, when the resolution of the rendering processing unit 103 or the print processing unit 107 is higher, the width of the edge portion is 2 pixels in order to obtain the effect according to the resolution, and the width for thickening the object can be up to 4 pixels in total. Is desirable. In the fourth embodiment, the width of the edge portion is set to 2 pixels, and the operation unit performs three-stage setting of “0 pixel”, “2 pixel”, and “4 pixel” in total as the setting of “width for thickening object”. Get from user. Then, an embodiment of an image processing apparatus that enables appropriate image processing after thickening the width of an object by a plurality of pixels as instructed will be described.

The configurations of the image processing apparatus 100 and the image processing unit 104 in the fourth embodiment are the same as those in the first embodiment. Portions having different processing contents from those of the first embodiment will be described.

The operation unit 106 acquires from the user three types of settings of “0 pixel”, “2 pixel”, and “4 pixel” as the setting of “width to thicken object”, and notifies the image processing control unit 105 of the setting.

The image processing control unit 105 determines, based on this setting information, that each unit of the image processing unit 104 determines “the position of the edge portion before thickening the object” and “the position of the edge portion after thickening the object”. The image processing unit 104 is instructed how to do this. The edge data generation unit 202 determines each position for the image data acquired from the memory buffer 201. That is, "the position of the edge portion before thickening the object", "the position of the edge portion after thickening the width of the object by 2 pixels", and "the position of the edge portion after thickening the width of the object by 4 pixels". To decide. Then, the edge data including the information is generated. Details of the processing of the edge data generation unit 202 for generating this edge data will be described later in [Description of the edge data generation unit 202 in the fourth embodiment]. The edge data generation unit 202 outputs the generated edge data to the thickening processing unit 203, the undercolor removal processing unit 204, the color material amount limitation processing unit 205, and the screen processing unit 206.

The edge data of the fourth embodiment has a bitmap format of the same size as the image data, and has 3 bits of information for each pixel. The first bit from the lower order is information about "the position of the edge portion before thickening the object". If the value is 0, the pixel is not the edge portion, and if the value is 1, the pixel is the edge portion. Is shown. In addition, the second bit from the lower order is information about “the position of the edge portion after the width of the object is thickened by two pixels”, and if the value is 0, it indicates that the pixel is not the edge portion, and the value is A value of 1 indicates that the pixel is an edge portion. In addition, the 3rd bit from the lower order is the information about “the position of the edge part after the width of the object is thickened by 4 pixels”, and if the value is 0, it indicates that the pixel is not the edge part, and the value is A value of 1 indicates that the pixel is an edge portion. As an example of the edge data in the fourth embodiment, edge data generated from the image data shown in FIG. 3A is shown in FIG. The edge data in FIG. 4D has 3-bit information for each pixel, but for convenience of explanation, the value of each pixel is represented by a decimal number. In FIG. 4D, since the width of the edge portion is 2 pixels, the pixel inside the inner edge is also at the position of the edge portion before the object is thickened. Details of the processing of the edge data generation unit 202 in the fourth embodiment will be described later.

Next, the undercolor removal processing unit 204, the color material application amount restriction processing unit 205, and the screen processing unit 206 will be described. These processing methods are the same as those in the first embodiment, but the method of determining "the position of the edge portion after thickening the object" is different from that in the first embodiment. In the fourth embodiment, the bit of the edge data indicated by "the position of the edge portion after the object is thickened" differs depending on the setting of the "width to thicken the object" set by the user on the operation unit. When the "width of thickening the object" is set to "0 pixel", the first bit of the edge data indicates "the position of the edge portion after thickening the object". When the “width of thickening the object” is set to “2 pixels”, the second bit of the edge data indicates “the position of the edge portion after thickening the object”. When the "width of thickening the object" is set to "4 pixels", the third bit of the edge data indicates "the position of the edge portion after thickening the object". FIG. 16 shows how to make this determination. The image processing control unit 105 instructs the thickening processing unit 203, the undercolor removal processing unit 204, the color material application amount restriction processing unit 205, and the screen processing unit 206 how to make this determination.

Next, the processing of the thickening processing unit 203 will be described. The thickening processing unit 203 also determines “the position of the edge after thickening the object” according to FIG. 16. Then, as the processing for thickening the object, first, a pixel which is “the position of the edge after thickening the object” is detected from the edge data. Then, using that pixel as a pixel of interest, a pixel indicating "the position of the edge before thickening the object" is detected within 2 pixels in the vertical and horizontal directions from that pixel. If such a pixel is found, the pixel value in the image data of that pixel is overwritten on the pixel of interest in the image data.

<Details of Edge Data Generation Unit 202 in Fourth Embodiment>
The flowchart of FIG. 17 showing the processing of the edge data generation unit 202 is shown. In order to simplify the description in the fourth embodiment, the “objects that will be combined when fattened” as shown in FIG. 9 considered in the first embodiment will not be considered.

First, in step S1701, the edge data generation unit 202 applies a Laplacian filter to the entire image data for each color material plate of the image data. This is the same processing as S501 in the first embodiment. Next, in step S1702, the edge data generation unit 202 performs threshold value determination on each pixel based on the calculated value of the Laplacian filter, and generates filter data. This is the same processing as S502 in the first embodiment.

Next, in step S1703, the edge data generation unit 202 determines, in the filter data, the inner edge and the non-edges vertically and horizontally adjacent to the inner edge as “the position of the edge before thickening the object”, and determines the edge data. To record. At this time, 1 is set to the first bit from the lower order of the pixel value of the corresponding pixel of the edge data.

Next, in step S1704, the edge data generation unit 202 determines that the inner edge and the outer edge in the filter data are “the position of the edge portion after the width of the object is thickened by 2 pixels”, and the edge data To record. That is, it is determined to be the position of the edge portion after the width of the object is thickened by 2 pixels in total. At this time, 1 is set to the second lowest bit of the pixel value of the corresponding pixel of the edge data.

Next, in step S1705, the edge data generation unit 202 determines, in the filter data, for the outer edge and the non-edges vertically and horizontally adjacent to the outer edge, “the edge after thickening the width of the object by 4 pixels. Position, and record it in the edge data. That is, it is determined to be the position of the edge portion after the width of the object is thickened by 4 pixels in total. At this time, 1 is set to the third least significant bit of the pixel value of the corresponding pixel of the edge data.

Finally, in step S1707, the edge data generation unit 202 outputs the edge data to the thickening processing unit 203.

As described above, according to the fourth embodiment, the width of the edge is set to 2 pixels, and the width of the object to be thickened is thickened in three stages of “0 pixel”, “2 pixels”, and “4 pixels”. It is possible to apply appropriate image processing.

(Other embodiments)
The object of the present invention is also achieved by performing the following processing. That is, a storage medium recording a program code of software that realizes the functions of the above-described embodiments is supplied to a system or apparatus, and a computer (or CPU, MPU, etc.) of the system or apparatus stores the storage medium in the storage medium. Is a process for reading.

In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiments, and the program code and the storage medium storing the program code constitute the present invention.

Claims (13)

An image processing apparatus for thickening the width of the object included in the image data,
Specifying means for specifying pixels on the inner edge inside the object from the image data and pixels on the outer edge outside the object;
By overwriting the value of the pixels in said edge of said object with respect to a pixel of said outer edge of said object specified by said specifying means, and thickening processing means for thickening the width of the object,
The object after the width is changed by the thickening processing means, and characterized in that it has a pixel of the outer edge specified by said specifying means, and an image processing means for performing predetermined image processing for edge Image processing device. The image processing apparatus according to claim 1, wherein the predetermined image processing is undercolor removal processing for replacing the undercolor with data of a predetermined color material . The image processing apparatus according to claim 1 or 2, wherein the predetermined image processing is a color material mounting amount restriction processing for restricting a total density of the color material per unit area . Wherein the predetermined image processing, the image processing apparatus according to any one of claims 1 to 3, characterized in that a screen process performed on the image data. The image processing means performs a screen processing of a first line number on the pixels of the outer edge, and a pixel number of the object other than the outer edge of the object is smaller than the first line number. The image processing apparatus according to claim 4, wherein the screen processing of the second number of lines is performed. The said specifying means specifies whether the pixel of the said object is an inner edge or an outer edge based on the value obtained by applying a Laplacian filter to the said image data. The image processing apparatus according to any one of 5 above. An image processing method of thickening the width of the object included in the image data,
A specifying step of specifying pixels on the inner edge inside the object from the image data and pixels on the outer edge outside the object;
By overwriting the value of the pixels in said edge of said object with respect to a pixel of said outer edge of said object specified by said specifying step, a processing step thickening thickening the width of the object,
The object after the width is changed by the thickening processing step, and characterized in that it has a pixel of the outer edge that is specified by the specifying step, and an image processing step of performing predetermined image processing for edge Image processing method. The image processing method according to claim 7, wherein the predetermined image processing is undercolor removal processing for replacing the undercolor with data of a predetermined color material. 9. The image processing method according to claim 7, wherein the predetermined image processing is a color material mounting amount restriction processing for restricting a total density of color materials per unit area. The image processing method according to claim 7, wherein the predetermined image processing is screen processing performed on the image data. In the image processing step, a screen processing of a first line number is performed on the pixels of the outer edge, and a pixel number other than the outer edge of the object is smaller than the first line number. The image processing method according to claim 10, further comprising performing screen processing with a second line number. 8. In the specifying step, it is specified whether the pixel of the object is an inner edge or an outer edge based on a value obtained by applying a Laplacian filter to the image data. 11. The image processing method according to any one of 11. Program for causing a computer to function as the image processing apparatus according to any one of claims 1 to 6.

Images